Abstract
It has been argued that domestication explains the ability of domestic animals to use human cues, but similar abilities exist in wild animals repeatedly exposed to humans. Little is known on the importance of the developmental stage of this exposure for developing such abilities. Orphancy and subsequent hand-rearing constitute a quasi-experimental situation for investigating this question. Cheetahs (Acinonyx jubatus) are interesting as they present a two-step development, spending their first two months of life in a den with occasional visits from the mother, and then accompanying their mother outdoors. Mother loss may occur at any of these stages, and the orphaned cheetahs are then taken under human care. We tested the importance of the stage of development on their long-term perception of humans by comparing the reactions of adult wild-born cheetahs, orphaned at "den-age" (Early-Orphaned, 0-2 months) or at a later stage (Late-Orphaned, 2-6 months), to motionless humans (familiar vs. unfamiliar). The results showed that Early-Orphaned, but not Late-Orphaned cheetahs, produced affiliative calls (purrs) towards humans and discriminated familiar and unfamiliar humans. Taken together, these results suggest that the timing in which an emotional bond is created with the primary caregiver (humans in the case of Early-Orphaned cheetahs and the mother in the case of Late-Orphaned cheetahs) is crucial in determining the reaction towards the species of the early caregiver throughout life.